Review: Shure GLX-D Advanced Wireless Microphone System

We found it to be ideal for church applications requiring just a few channels of wireless (up to a maximum of 11) or for adding to an existing house of worship system operating in another frequency band.

Given Shure’s depth of experience in designing wireless microphone systems over the past few decades, the new GLX-D Advanced system is like a “greatest hits” compilation – combining their advances in digital transmission from the PGX-D through ULX-D wireless operating in the UHF spectrum, their frequency management and transmitter battery charging technologies from the Axient line, the durable transmitter and receiver design from the entire professional range, automatic transmitter and receiver linking, and the use of the 2.4 GHz spectrum from this new system’s predecessor. It’s a very good sounding and well-built system that should serve the needs of church users who require only a moderate number of wireless channels, or desire to add more systems to their existing complement by going to another frequency band.

Shure has designed this system with houses of worship, educational institutions, and similar users in mind, with a mission of “seamless digital audio for small-to-medium-size spaces.” To continue from their web site, “the suite of products automatically scans, coordinates, deploys, and updates wireless receivers and transmitters during setup and use… …this means the freedom to focus on your message…” Let’s take a look at how they’ve gone about this task.

Overall System

The GLX-D Advanced system consists of the GLXD4R half-rack receiver, the GLXD1 beltpack transmitter, the GLXD2 handheld transmitter, and the UA846Z2 frequency manager unit, plus a variety of antenna and microphone options. Several systems may be used in stand-alone mode, if that is enough to meet your church's needs. However, to achieve the greatest channel count and fully take advantage of the automatic frequency selection and interference protection, connecting the receivers to one (or two, for systems above six channels) frequency manager unit is necessary. Doing so will also allow the receivers to be powered and receive the RF signal via the manager, versus the “antenna farm” look of multiple stand-alone receivers.

Once you get the hang of the process, this is the fastest battery change I’ve experienced.

GLXD4R Receiver

My test system included two receivers, a handheld and beltpack transmitter, and the frequency manager. The half-rack receiver is housed in a hefty metal chassis, and provides all the necessary features to link with the transmitter and connect to the audio system and other wireless units. It doesn’t offer the depth of features found in products like the ULX-D or Axient, nor does it need to for its intended purpose.

The front panel features an LCD display that shows the currently selected group and channel, output gain level, audio level from the transmitter, battery level (in hours and minutes), and transmitter lock status. Buttons are provided to manually link to a transmitter and select a group and channel, and to raise or lower the output gain, along with related indicator lights. An on/off button and battery charging slot complete the picture.

The rear panel has an unbalanced quarter-inch TRS connector and a balanced XLR with a mic/line output level switch, antenna A/B connections, a locking external power connector, and a mini-USB port for software upgrades. I really like the threaded locking feature on the “barrel” power connector, because the connection is quite solid and cannot be accidentally disconnected. The same can be said for the threaded reverse SMA antenna connectors.

It offers wide and natural frequency response with no hint of background noise

The receiver incorporates frequency scanning, with the ability to search the full 2.4 GHz WiFi band and determine clear spectrum. Pressing the Channel button activates the process, and after a few seconds a selected group and channel will be set. To manually change the group and channel settings, you can hold that same button for a couple seconds and then scroll through the alternatives using the Group and Channel buttons. When combined with the frequency manager unit, the scanning process will select a set of compatible channels for all of the connected wireless receivers, along with backup frequencies that are then automatically assigned.

The GLX-D Advanced has the ability to manually select from four different groups, if you’re not using the frequency manager. Group 1 offers up to four channels with three backup frequencies per channel (the initial factory setting), Group 2 accommodates five channels with backup, and Group 3 allows up to eight channels but without backup. Group 4 is for ultra-reliable single-channel use, with 27 backup frequencies that will be seamlessly assigned in case the current frequency experiences interference. To operate more channels of wireless simultaneously, and for system-wide frequency management, adding the frequency manager is recommended.

A rack-mounting kit is included, so that either a single receiver or two side-by-side receivers can be mounted in a 1RU space. This kit is designed to create a strong and stable mounting, made from heavy-gauge metal and with flanges that screw into the top and bottom edges of the receiver for added security. Top and bottom plates are provided to hold two receivers together with no possibility of sagging. As with other aspects of this system, rack-mounting is roadworthy and neatly designed.

GLXD1 Beltpack and GLXD2 Handheld Transmitters

The GLXD1 beltpack transmitter is compact, with a sleek appearance, yet has some heft with its cast-metal construction. It should easily shrug off the tribulations of constant use. This durability extends to the spring-wire belt clip, which is solidly attached to the transmitter chassis and holds firmly on a belt or guitar strap.

If you discover at the last minute that you have a fully discharged battery pack, we that just 15 minutes of charging in the receiver will yield up to an hour and a half of transmitter use.

The transmitter itself has few visible features. A short, covered antenna projects from the top, and the TA4M (4-pin mini XLR) is secured with a threaded inset nut. The strong connection won’t wiggle even with pressure or a drop when a guitar or headset mic cable is attached. A thin, low-profile but decidedly solid on/off toggle switch projects from the top adjacent to this connector. The status LED next to the switch lights solid green when the transmitter is on and linked to a receiver, and flashes when a link has not been established. A rectangular rubber pad on the side edge conceals a mini USB connector for in-beltpack battery charging and firmware upgrades, along with a manual Link button.

On the bottom, a heavy-duty battery door opens with a sideways slide of a switch along with a simultaneous slide perpendicular to the switch movement – once you get the movement in your fingers, it’s very easy to access but impossible to open accidentally. The custom lithium battery slides in and then is ready to close and use in moments. Once you get the hang of the process, this is the fastest battery change I’ve experienced.

The GLXD2 handheld transmitter is also a study in simplicity and robustness. From mic head to antenna, it measures a bit under ten inches. Though the handheld isn’t as elegant in appearance as the beltpack, at least with the round SM58 mic head in place, it is nicely designed, solid, and practical in its feature set. The transmitter body feels good in the hand – well-balanced and nonslip – and is made of an extremely strong plastic for weight reduction with high durability. The only outside control is a recessed on/off slide switch, with a status LED above it.

The lower part of the handle twists to unthread, exposing a battery compartment for the rechargeable pack, along with a USB connector for charging and upgrades, and a manual link button. The transmitter is available with four mic head choices – the SM58 and Beta 58 dynamics, or the SM86 or Beta 87A condensers.

The rechargeable battery system is elegant, permitting charging within the transmitter or in the receiver’s charging bay. The transmitters will function for up to 16 hours on a fully charged battery, and the receiver displays the remaining time in hours and minutes. A full charge takes three hours in the receiver bay, or four via the USB connection in the transmitter. And just 15 minutes of charging in the receiver will yield up to an hour and a half of transmitter use, if you discover at the last minute that you have a fully discharged battery pack.

Another safeguard within the system is that the transmitter on/off switch can be locked to prevent accidental turnoff, either at the transmitter itself, or remotely via its linked receiver.

The Frequency Manager

The UA846Z2 frequency manager for the GLX-D Advanced wireless system is literally a “black box”, measuring 1RU and rack-mountable as delivered. The front panel features only an on/off switch and a power LED. The rear panel contains a group of threaded, locking connectors to power up to six attached receivers, and threaded connectors for the A and B diversity antennas of those receivers. When connected to two frequency managers, the GLX-D Advanced offers up to 11 channels of simultaneous wireless. The system contains all necessary cables to make those connections, and hardware to front-mount the antennas.

The “secret sauce” is how the frequency manager coordinates the communications among the connected receivers and responds to interfering radio signals from the church next door by automatically changing frequencies on the affected receivers and their linked transmitters, seamlessly and in real time. The initial setup takes a few minutes to connect the power and antenna ports to the receivers. Once you’re set up, it is just a matter of turning on the first connected receiver, selecting frequency group A or B (B provides the option for a few more simultaneous channels at the cost of perhaps three microseconds of additional latency), and then linking transmitters to receivers one by one.

Once this process is complete, turning on the frequency manager will also turn on the receivers, and the transmitters will connect to their linked receivers when activated -- great for those volunteer church sound engineers. If you need to make changes, such as linking a new transmitter to a receiver, use the manual linking procedure.

Since the connections between the frequency manager and the receivers are short, they will reside in the same rack. If the area where the transmitters will be used is at some distance or out of line-of-sight, attaching omni or directional remote antennas to the frequency manager and placing them nearer the action is beneficial.

How Does It Perform?

In audio terms, the GLX-D Advanced system sounds very good, with a wide and natural frequency response with no hint of background noise. The gain control buttons on the receiver front panel cover a range of -18 to +42 dB, so the level can be sufficiently adjusted to obtain a good signal level without overload and digital distortion. In our evaluation, the system sounded great with spoken and sung vocals, and with acoustic guitar.

The frequency coordination system is smart and guards against mistakes. Once a transmitter is linked to a particular receiver, the system “knows” and retains this combination. You can turn on another transmitter near that receiver when its linked transmitter is off, and it will not automatically link to the receiver; it will take a manual process to link the new transmitter. You can use this process to link a second transmitter to a receiver, in case you want a “combo” system, where you would use a handheld or a beltpack at different times with the same receiver. Also, with an already linked transmitter, you can change the group and channel on the receiver, and then turn on the transmitter – which then links and changes to the new channel in a couple seconds.

And if a receiver’s Link button is accidentally pushed while linked with a transmitter, the wireless connection will remain solid, whether or not the transmitter is turned on at the time. Another safeguard within the system is that the transmitter on/off switch can be locked to prevent accidental turnoff, either at the transmitter itself, or remotely via its linked receiver. Receiver controls can also be locked, and this locking is unaffected by power cycles. So a full system can be set up and then locked so that it will perform just as well for mid-week worship team rehearsals as it will for your weekend church services.

The Bottom Line

The GLX-D Advanced is a well thought out and easy to use 2.4 GHz wireless system, that offers several channels of good sounding wireless audio, with the durability to last most churches for many years. The automatic frequency selection with backup, long transmitter battery life, and flexible options are all pluses. It is ideal for applications requiring just a few channels of wireless (up to a maximum of 11) or for adding to an existing system operating in another frequency band.

I would consider it a mid-priced wireless system, with list prices per channel ranging from the mid $600’s to a bit over $900, depending on the system configuration. For example, Shure tells us the handheld system with an SM58 head has a street price of about $599. The list price for the frequency manager is $524. All in all, this truly advanced 2.4 GHz wireless system seems worthy of the investment.